Large-Scale Complementary Logic Circuit Enabled by Al₂O₃ Passivation-Induced Carrier Polarity Modulation in Tungsten Diselenide

Abstract

Achieving effective polarity control of n-and p-type transistors based on two-dimensional (2D) materials is a critical challenge in the process of integrating transition metal dichalcogenides (TMDC) into complementary metal-oxide semiconductor (CMOS) logic circuits. Herein, we utilized a proficient and nondestructive method of electron-charge transfer to achieve a complete carrier polarity conversion from p-to n-type by depositing a thin layer of aluminum oxide (Al 2 O 3 ) onto tungsten diselenide (WSe 2 ). By utilizing the Al 2 O 3 passivation layer, we observed precisely tuned n-type behavior in contrast to transistors fabricated on the as-grown WSe 2 film without any passivation layer, which display prominent p-type behavior. The polarity-transformed ntype WSe 2 transistor from the pristine p-type shows the maximum ON current of ∼0.1 μA accompanied by a high electron mobility of 7 cm 2 V −1 s −1 at a drain voltage (V DS ) of 1 V. We successfully showcased a homogeneous CMOS inverter utilizing 2D-TMDC which exhibits an impressive voltage gain of 7 at V DD = 5 V. Moreover, this effective polarity control approach was further expanded upon to successfully demonstrate a range of logic circuits such as AND, OR, NAND, NOR logic gates, and SRAM. The proposed methodology possesses significant promise for facilitating the advancement of high-density circuitry components utilizing 2D-TMDC.

Emerging Schemes for Advancing 2D Material Photoconductive-Type Photodetectors

“…As an example, it is revealed that the SnSe field-effect transistor with an h-BN encapsulation layer exhibits substantially reduced hysteresis as compared to a bare SnSe device [123]. In addition, Das et al demonstrated that the mobility of an Al 2 O 3 -passivated WSe 2 field-effect transistor is ≈5.5 times that of a bare WSe 2 device [124].…”

In-sensor neuromorphic computing using perovskites and transition metal dichalcogenides

“…Various materials, oxide, gallium arsenide, perovskite, graphene, TMDs, porous crystalline, biological, and organic materials have been employed in the development of the high-performance neuromorphic devices [11][12][13][14][15]. Among them, perovskite and TMD materials have attract broad attention due to the diversity, high charge carrier mobility [16][17][18][19][20][21][22][23][24][25], and excellent optoelectronic characteristics [26][27][28][29][30][31][32]. Despite the exceptional stability, compact cell size, high integration density, flexible temperature sensitivity and remarkable stability exhibited by metal oxide-based neuromorphic devices [33][34][35][36][37][38], their functionality remains relatively subpar, particularly in terms of optoelectronic response properties.…”

Lateral homojunctions of WSe2 through contact surface engineering with SF6 plasma etching

“…However, the ion-implantation, a processing widely used in silicon technology for precise doping, is of little use in doping ultrathin 2D semiconductors of layered transition metal dichalcogenides (TMDs), which has triggered noticeable research efforts towards alternative mechanisms. So far, various approaches such as chemical doping, 13 plasma doping, 14 metal contact doping 15–17 and spacer doping 18–20 have been explored to achieve different doping for lateral/vertical p–n homojunctions based on mechanically exfoliated WSe 2 or CVD-grown species.…”